In conventional, as a structure for supplying a liquid filler filled in a filling region in an inner portion of a container, to a brush in a leading end of the container, there has been known a structure obtained by integrally forming a ring-like base portion (a holder portion) attached to a leading end side within a container, and a tubular portion (a pipe portion) in which a rear end is connected to the base portion and a leading end is inserted to a brush (for example, refer to Japanese Unexamined Patent Publication No. 10-165878). In the structure mentioned above, it is necessary to make the pipe portion thin in order to make an outer diameter of the brush smaller.
In this case, the integrally formed product constituted by the holder portion and the pipe portion is generally formed in accordance with an injection molding. In this injection molding, the integrally formed product mentioned above is obtained by preparing a forming die provided with shapes corresponding to the holder portion and the pipe portion, injecting a molten resin through a resin injecting port provided in a portion of the forming die in correspondence to a rear end surface of the holder portion at a predetermined pressure, and releasing from the mold after being solidified.
However, in the integrally formed product mentioned above, since the pipe portion is thin and long, the molten resin from the holder portion is hard to uniformly flow toward the leading end of the cylinder portion of the pipe portion, and a difference is generated in a cooling time between the cylindrical portion through which the resin first flows and the cylinder portion through which the resin flows later, so that the pipe portion is curved after being cooled and solidified. Further, in the case of forming at a higher pressure than necessary in order to uniformly fill the molten resin in the pipe portion, an excessive load is applied to a narrow core pin for forming an inner peripheral surface of the pipe portion so as to bend the core pin, and the forming die is broken.